This invention relates to methods and apparatus permitting the prevention of and arresting of the progress of burn injuries, and creating an environment conducive to wound healing for acute and chronic wounds.
Burn injuries may be caused by exposure to heat, chemicals, electricity, or radiation, including solar radiation. Burn injuries are classified by the depth of penetration into the skin and underlying structures as well as the extent and location of the injury. The presence or absence of pain is not a good indicator of burn severity since very severe burns may be relatively pain-free due to extensive damage to the nerve endings.
When burn injuries occur, emergency treatment can help alleviate pain and can reduce the severity of after-effects of burn damage. Recommended emergency treatment methods often include the twin goals of preventing infection and cooling the burn site.
Since the skin is the first tissue to receive damage from burns, the loss of skin function creates most of the after-effects of burn damage. For example, intact, functioning skin provides a fluid barrier to prevent loss of body fluids. Large burn wounds can result in dehydration from fluid loss due to non-functioning, or nonexistent skin. Maintenance of moistness of the wound area is thus often desirable to prevent dehydration. Additionally, when a burn wound area is allowed to dry, movement of the area and surrounding skin is often very painful. When burn wounds are more localized, movement of the burn site is common. This is particularly true where the burn injury extends over an area where the skin is stretched as a joint is moved. Treatment methods currently employed do not often account for the flexure of a joint. Instead they may rely on immobilization of an entire patient, such as the treatment method disclosed in U.S. Pat. No. 3,986,505 issued to Power. The treatment method disclosed in Power teaches wrapping the patient within a sterile sheet and then enclosing the patient in a waterproof covering for transport. For smaller burn wounds, this method of treatment may be impractical.
To maintain moisture around a smaller wound, a local covering may be used. Typical materials used for covering, however, are generally made from a fabric or woven type material. These materials will not stretch, and hence limit movement of a burn site and apply unnecessary pressure on a burn site.
Of greatest threat, however, are the sometimes life threatening, complication of burn wounds due to infection. One of the primary functions of skin is to prevent contaminants from entering the body. When this protective barrier is lost due to burn injury, contaminants from multiple sources are free to enter the body and cause infection.
One goal of any emergency treatment method should thus be to prevent or reduce infection. This goal is usually achieved through limiting the contaminants entering the burn wound. Contamination may occur from clothing or debris that becomes embedded within the burned tissue. While this type of contamination may be washed away through emergency treatment methods under certain circumstances, removal and treatment for this type of contamination must usually wait until a patient can receive medical treatment at an appropriate facility.
Contamination may also occur while the burn wound is exposed to a non-sterile environment or from application of non-sterile coverings. While covering the burn wound is usually desirable, material that is applied to the burn wound may become saturated with leaking fluid. Subsequently, the material may adhere to the wound such that removal is very painful and possibly causes additional tissue damage. Moreover, depending on the nature of the material, shreds or fibers from the material may remain adhered to the wound and necessitate more extensive painful debridement. In addition, ever present airborne bacteria may enter the wounds of a burn patient while the tissue is unprotected by skin or dressings. It would therefore be advantageous to provide burn dressings that help keep bacteria from infecting a burn site while not adhering to the wound.
Heat generated at a burn site continues to damage the tissue even after removal from the direct burn injury source. Cooling the burn site helps to arrest the damage and can reduce the overall severity of the damage from a burn injury. Accordingly, a recommended immediate treatment of a burn wound is the gentle and continuous application of cool water. Application of cool water generally results in lessening of the pain and may cool the tissue enough to lessen the progression of the damage. Water, however, quickly flows away from the burn site and must be constantly replenished. Additionally, ice or ice water should not be used because of the risk of critical loss of body heat, and further potential tissue damage.
If continuous application is not possible, then repeated application of wet compresses is often suggested. These compresses must be kept cool with more water, however, as they will quickly absorb heat from the tissue. To provide as much cooling to the burn site as possible, the material used for the compresses should be capable of conforming to the shape of the burn site. Unfortunately, the fabric and woven material typically available for use in wet compresses do not conform well to areas that can be flexed or bent, such as joints of the limbs. Furthermore, the more complete the contact with the wet compresses, the greater the risk that the compresses will become saturated with leaking body fluid and stick to the burn wound.
Depending on the circumstances, clean cool water may not be immediately accessible or the patient's condition or location may make continuous application to the burn wound difficult or impossible. A method of transporting a burned patient in a sterile, moist environment such that the patient is kept cool and clean is disclosed in U.S. Pat. No. 3,986,505 issued to Power. Power teaches the use of a foam material saturated with an aqueous solution disposed within a flexible waterproof covering. The burned patient is essentially wrapped in a sterile sheet saturated with aqueous solution, positioned upon the foam material, and then enclosed within the flexible waterproof covering prior to transport. As previously mentioned, however, where the burn is relatively localized, this method of treatment may be impractical.
Another problem associated with burn victims is extinguishing burning clothing that may become ignited by exposure to a heat source. U.S. Pat. No. 3,902,559 issued to Everinghingham et al., herein incorporated by reference, discloses a means of extinguishing burning clothing on humans comprising application of a fabric carrier saturated with an aqueous solution of a thickening agent.
The above-described approach permits extinction of a fire source and swathing of the patient in a moist environment. The covering provides protection from environmental contamination and the moistness promotes some cooling effect. However, neither of the above-described approaches effects significant lowering of the intradermal temperature at the burn wound site.
It would, therefore, be advantageous to provide methods and apparatus for improved treatment of a burn wound that permit significant lowering of the intradermal temperature within the burn wound and maintenance of a lowered intradermal temperature within the burn wound such that the extent of the burn wound may be limited and the patient be more comfortable. It would additionally be advantageous to provide means for substantially reducing the intradermal temperature through the application of a burn wound treatment composition that also inhibits infection, promotes healing of the tissue, and is easily removed with water so that removal does not cause the patient additional pain or tissue damage. Moreover, it would be advantageous to provide this capability with a flexible material that conforms to the burn site and stretches when the site is moved so that no unnecessary pressure is exerted on the burn site.
A potential side effect of reducing of the intradermal temperature is hypothermia. Therefore, it would also be advantageous to provide a system that is effective at reducing intradermal temperature without the threat of overcooling, heat loss, and ensuing hypothermia.
Acute and chronic wounds include pressure ulcers (decubitus or bed sores), venous and arterial ulcers, and diabetic ulcers. Pressure ulcers are the most common form of skin damage and occur when externally applied pressure exceeds capillary closing pressure. With the unrelieved pressure, tissue damage occurs, creating a wound. This type of wound is most common in people whose general health has been compromised and usually occurs over a bony prominence. Pressure ulcers are often found in patients who are confined to bed or wheelchairs. It is estimated that the treatment of pressure ulcers costs the U.S. healthcare system over 8.5 billion dollars annually. Venous and arterial ulcers generally occur on the legs or feet and are the result of some type of vascular damage. These wounds occur most frequently when a combination of poor blood flow and high blood pressure exist. Diabetic ulcers are sores that occur on the foot of a patient with diabetes. They have many contributing factors including trauma, poor circulation, and an abnormality of the nervous system. Current treatment protocols involve the use of products that provide a moist wound environment.
In 1961, George Winter first experimented with the promotion of a moist wound environment in the treatment of injury. His experiments showed that by keeping the wound surface damp, healing was accelerated. This result was first published in medical journals in 1971. The first hydrogel was not commercially introduced until 1985. Many now consider a moist environment preferable in the treatment of wounds. Research data suggest that the body's natural healing processes of autolytic debridement, epithelialization, granulation, and maturation are enhanced in a moist environment. Healing can occur more quickly in a moist healing environment than in wounds left exposed to air. However, the threat of infection remains an ongoing concern, and, typically, products that are bacteriostatic unfortunately are also cytotoxic. In other words, they inhibit or stop the growth of new skin cells, thus slowing the wound-healing process.
Many health care providers do not use a moist protocol for infected wounds because a moist environment has been shown to be conducive to growth of bacteria. It would, therefore be advantageous to provide methods and apparatus for improved moist treatment of an infected acute or chronic wound that would inhibit the growth of bacteria, while not inhibiting the growth of new cells. In addition, odor control in chronic wounds has become an important concern of health care workers and caregivers. An added advantage in this apparatus would be to help maintain an odor free wound site.
In view of the foregoing, it will be appreciated that providing methods and apparatus for treating wounds with a moist environment while inhibiting microbial infection and odors would be a significant advancement in the art.